Impact of a voluntary industry code for advertising food to children and young people: an analysis of New Zealand television data.

Objective: To evaluate the impact of the 2017 update to the voluntary Advertising Standards Authority (ASA) code for advertising food on children and young people's exposure to unhealthy food advertisements on New Zealand television.

Design: Audience ratings data were analysed for New Zealand children and young people's television viewing for eight random days prior to (June to August 2015) and following (October to December 2018) the code update, from 06.00 to midnight (864 h). Food advertisements were coded using three nutrient profiling models. The number of children and young people watching television each year was compared.

Setting: Three free-to-air New Zealand television channels.

Participants: New Zealand children aged 5-18 years.

Results: Television viewer numbers decreased over the 3 years (P < 0·0001). The mean rate of unhealthy food advertising on weekdays was 10·4 advertisements/h (2015) and 9·5 advertisements/h (2018). Corresponding rates for weekend days were 8·1 and 7·3 advertisements/h, respectively. The percentage of food advertisements which were for unhealthy foods remained high (63·7 % on weekdays and 65·9 % on weekends) in 2018. The ASA definition of children's 'peak viewing time' (when 25 % of the audience are children) did not correspond to any broadcast times across weekdays and weekend days.

Conclusions: Between 2015 and 2018, children and young people's television exposure to unhealthy food advertising decreased. However, almost two-thirds of all food advertisements were still unhealthy, and the updated ASA code excluded the times when the greatest number of children was watching television. Consequently, government regulation and regular monitoring should reflect the evolving food marketing environment.